For the log: Today my 121 (a 122 with 4 doors and one carb) start uneven. The idle speed travel between 800 and 1200 rpm. Some explosions on the exhaust. On first I suspect problems on some cylinder or a air source on the inlet manifold.

After some tests, I´ve no clue about the source, and come to make a more organized analysis. Oh,Oh, as part of the protocol, I check the spark (hanging the cable from the coil a centimeter over the engine chromed cover)...no spark. The fiber core was boken... I change that cable with a solid copper center one (here available on some old shops), voila! - as a safety measure, I change all ignition cables from distributor to spark plugs also to copper solid center - a bit of very low noise on AM radio, FM radio ok, engine run a lot more smooth than before.

Reading about the ignition, now I know that the original ignition cables on the 121 and 122 was copper solid center...it was a return to origins.

Joaquin
Rojo 121 Amazon
Lima Peru